Field of the Invention
This invention relates to emergency egress systems and, more particularly, to novel systems and methods for rapidly evacuating an area of multiple workers using a zip line.
Background Art
The word “zipline” and words “zip line” refer to a line, such as a wire rope, steel cable, fiber rope, or the like as a “track line,” typically suspended as a catenary between two supports. A catenary is a well defined and understood term in structural and civil engineering, used here in that ordinary meaning.
A zip line necessarily contains no intervening supports. It typically relies on gravity, although some short lines may be more level. Some lines lacking sufficient (or having zero) decline between a start point and end point may rely on a rider. A rider or riders may move the trolley by drawing on the track line directly, or drawing on a nearby and nearly parallel line, by hand-over-hand grasping and pulling on the appropriate line. That motion is relative, whether the cable is fixed or not. All lines may be fixed at their ends. Lines may be run around pulleys at each end. In some instances, an attendant on the ground below a zip line may draw a rider and trolley along a zip line. Such attendants may draw a rider on an uphill portion near the lower end thereof, in order to move the rider along. An attendant may apply a braking force on a moving rider and trolley.
Adventure stories, action movies, military operations, and the like may rely on zip lines as lightweight, temporary mechanisms for crossing a space, such as a river or gorge. An individual rider may use a gloved hand for their own braking. One may move along a cable or line by grasping the overhead line with a gloved hand. In other instances, a long braking rope extends downward to be grasped at an appropriate time and place by an operator below. The operator grips the rope to restrain or to exert force on a rider, thereby slowing the rider from crashing into the lower anchor on the ride.
Frequency of use, rider ability, panic, skill, comfort with speed, or the like, and the presence of multiple riders accessing, launching, and riding seats simultaneously create risks affecting operation and safety. Overweighting a catenary near a single location distorts its shape, altering clearance above a deck or other surface therebelow. This creates problems for riders needing to stage loading and launching from a pre-determined height of a deck structure.
In addition, zip lines have traditionally been a solo ride device. Brakes accessible to a rider have been largely absent. Absent, and now needed, is an ability to control an individual trolley on a track line, and safely accommodate short distances and possible impacts between trolleys of multiple riders loaded, launched, and rolling simultaneously on a single line from a single loading deck.
What are needed are apparatus, systems, and methods to render practical, safe, reliable, and consistent the unattended use of multiple trolleys launching simultaneously from a single loading deck to rapidly load and carry away workers from a location that has suddenly become dangerous, where time is of the essence and conventional exit is not practical.